Thermostat.



J. H. ROYALL.

THERMOSTAT.

APPLICATION FILED AUG.3, 1914.

Patented Dec. 28, 1915.

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JOHN H. ROYALL, 0F HOUSTON, TEXAS, ASSIG-NOR OF TWENTY-FOUR ONE-HUN- DREDTHS T0 G. W. E..MEBE'WETHER, 01 DALLAS, TEXAS, AND TWENTY-FOUR ONEHUNDREDTHS TO'J. R. MAXFIELD, OF WACO, TEXAS.

THERMOSTAT.

Specification of Letters Patent.

Patented Dec. 28, 1915.

Application filed August a, 1914. Serial No. 854,620.

To all whom it may concern Be it known that I, JOHN H. Forum, a citizen of the United States, residing at Houston, in the county of Harris and State of Texas, have invented certain new and useful Improvements in Thermostats, of which the following is a specification.

My invention relates to a new and useful thermostat, and its object is to provide a device that will be positive and automatic in may include an alarm signal) when the temperature of the instrument is abnormally raised, the instrument being further adapted in a slightly modified form to also indicate by closing an electric circuit -a temperature below a given standard.

It is another object of my invention to provide a device of the character described, that will be strong, durable, simple and efficient and comparatively inexpensive to produce, and also one that will not be likely to get out of working order.

5 With these and various other objects in ,view, my invention has relation to certain novel features of the construction and operation, an example of which is described in the following specification, and is illustrated in the accompanying drawing, wherein:

i Figure 1 is a front view of my thermostat, a portionof its casing being broken away to reveal the construction underlying the same. Fig. 2 is a bottom view of the thermostat,

the bottom wall of the casing being removed to show the interior construction. Fig. 3 is a} vertical sectional view taken upon the line ai -w of Fig. 1. Fig. 4 is a horizontal sectional View on y-y of Fig. 1. Fig. 5 is a fragmentary plan view showing a modified form of my invention. Fig. 6 is a view similar to Fig. 2 showing the modification. Fig. 7 is adetail perspective view, showing the mounting of a certain spring embodied in my invention.

Referring now more particularly to the drawing, wherein like reference characters designate similar parts in all the figures, the numeral 1 denotes the, rectangular base 'of my instrument, in which are formed apertures 1 to receive the screws, whereby said base may be vertically mounted upon a wall.

Upon said base respectively adjacent to each corner is mounted an angular bracket comduct-or 7 passing through an orifice 8 in the plate 1 has contact with one of the members 2 as is shown clearly in Fig. 1.

Midway between the extremities of the spr ng 5, there is surmounted upon said spring a U-shaped bracket 9, said bracket being secured to the spring 5 by a clamping member 10 (see Fig. 7). Between the up standing side pieces of the bracket 9, there is extended a pin 11, upon which is loosely mounted a bearing 12 rigidly secured to the lower end of an elongated vertical spring 13. The spring 13 projects at its lower end a short distance below its point of pivotal support, and this end is held permanently 1n contact with the front surface of the spring 6 by a leaf-spring l3 mounted upon the base-plate 1 behind the spring 13, and exerting a light forward pressure upon the lower end of said spring 13. The upper or free end of the spring 13 is normally slightly spaced from the head of an adjusting screw 14 mounted in a binding post 15 secured upon the base-plate 1 adjacent to its upper edge. The base-plate 1 and the mechanism mounted thereupon are inclosed within a perforated casing 16 secured to the member 1 by a pair of screws 17, the front of the casing-being held in its proper spaced gglation to the base plate by spacing sleeves hen the temperature of the two springs 5 and 6 is raised, there will be an'expansion of said springs proportionate in its magnitude to the increase of temperature. The

adjustment is such that when the temperathus carried toward the base whileits lower end is shifted from. the base. This will result in a slight angular displacement of the member 13 suiiicient to bring its upper end into contact. with .the'adjusting screw 14,

thereby closihg the electric circuit, one wire .19 of which "comes through the orifice 8 close an electric circuit-when the temperature of the instrumentjallsbelowa certain point, the lower'iiidicating spring will be bowed toward. the base 1 and the upper spring bowed front-said base as is indicatedat 20' and 2l'respect'i velyin Figs. 5 and 6.1 In this instance the lower end of the. mem-' ber 13 will be pivotally supported upon the lower spring'20i, and justabove its pivotal point, said member 13 will have contact with the rear face of the spring 21-; This con-- struction being followed, it is obvious that the members 20 and 21 ncontracting tend to shift the pivot point of the member 13 from the plate 1 and the point of contact of 30 said member 13 with the spring 21 is Shiftedtoward said .base plate. '-'By properly .ad-,

justing the screw ll, thefupper' end of the spring 13 will come-into contact with said screw when"- the temperature of the instru. ment islowered to a certain degree.

The invention is presented as including all such modifications and changes as prop-i name to this specification-in the presence of erly come within the-scope of the following claims.

What I claim is':-

1. A thermostat, comprising a pair of ad I jacently' mounted oppositely curved bowed springs held against longitudinal movement,

tact with" said terminal.

the distance between the ends of each spring being constant, of an elongated circuit closing member having oneextremity pivoted upon one of said bow springs at the middle thereof, said member having contact adja cent to its pivoted point with the center of the other bow spring, a spring acting on said member maintaining such contact, a 2

terminal normally spaced from the free end of the closingmember, and a circuit nor- 'mally broken between said terminal and the circuit closing member, a slight relative motion' between the two bow springs serving to close said circuit.

2. A thermostat, comprising a base plate,

a pair of spaced'brackets rigidly secured to said'plate, a pair of adjacent oppositely curved'bow springs distended between said brackets and. held against longitudinal movement therein, a bracket secured to one of said bow springs at its center, an elongated circuit closing member transverse With said bow springs, one of'its ends being pivotallysupported in said bracket, said memnormally spaced from thefree end'of said member, a circuit normally broken between said terminal and the circuit closlng memher, a slight'relative motion between the center portions of the bowrsprings subjectingfthe circuit closing member to an angular .ber being contiguous with the other bow I displacement bringing its-free end into con- 

